Sibyl Robinson hears the evening news that Quebec's Lagado government has called a referendum it hopes will separate the French province from Canada. Upset by the announcement the unilingual anglophone leaves her flat on Cumae street and walks her dog Trio through Montreal's Little Burgundy district down to the Lachine Canal. On the way home she discovers the slain body a black youth in a school yard near her flat. Packets of cocaine are found in the boy's pockets and police assume the killing to be drug related.
Sibyl's concern over the murder of 'one of her people' leads her to a friend of the slain youth and the two set out to find the killer. Their unusual investigation leads to officer Jean-Luc Turcotte as the culprit. He has been stealing confiscated cocaine from a police lock-up and soliciting black neighborhood youths to deliver the drugs to his selected customers.
Detective lieutenant Marc Kelly is assigned to the case and Jean-Luc is eventually charged with the youth's murder. Sibyl who becomes a chief witness for the defense breaks with her son Mark when he decides to defend the white officer. A rather bizarre trial ensues and Jean-Luc is acquitted.